English verb conjugation
CAN BUTTER

Regular verb: butter - buttered - buttered

Affirmation

Simple form	V-ing form
I can butter you can butter she can butter we can butter you can butter they can butter	I can be buttering you can be buttering she can be buttering we can be buttering you can be buttering they can be buttering
Perfect	V-ing perfect
I can have buttered you can have buttered she can have buttered we can have buttered you can have buttered they can have buttered	I can have been buttering you can have been buttering she can have been buttering we can have been buttering you can have been buttering they can have been buttering

Negation

Simple form	V-ing form
I can't butter you can't butter she can't butter we can't butter you can't butter they can't butter	I can't be buttering you can't be buttering she can't be buttering we can't be buttering you can't be buttering they can't be buttering
Perfect	V-ing perfect
I can't have buttered you can't have buttered she can't have buttered we can't have buttered you can't have buttered they can't have buttered	I can't have been buttering you can't have been buttering she can't have been buttering we can't have been buttering you can't have been buttering they can't have been buttering

Interrogative form

Simple form	V-ing form
can I butter? can you butter? can she butter? can we butter? can you butter? can they butter?	can I be buttering? can you be buttering? can she be buttering? can we be buttering? can you be buttering? can they be buttering?
Perfect	V-ing perfect
can I have buttered? can you have buttered? can she have buttered? can we have buttered? can you have buttered? can they have buttered?	can I have been buttering? can you have been buttering? can she have been buttering? can we have been buttering? can you have been buttering? can they have been buttering?

Interro-negative form

Simple form	V-ing form
can't I butter? can't you butter? can't she butter? can't we butter? can't you butter? can't they butter?	can't I be buttering? can't you be buttering? can't she be buttering? can't we be buttering? can't you be buttering? can't they be buttering?
Perfect	V-ing perfect
can't I have buttered? can't you have buttered? can't she have buttered? can't we have buttered? can't you have buttered? can't they have buttered?	can't I have been buttering? can't you have been buttering? can't she have been buttering? can't we have been buttering? can't you have been buttering? can't they have been buttering?